JP2010019891A - Toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner that maintains an initial tone while preventing fading even when an image is left in a severe environment such as long-term exposure to light and that vividly reproduces the original tone. <P>SOLUTION: The toner is prepared by using a colorant having a number average primary particle diameter of 30 nm to 200 nm and having a number average particle diameter included in the toner as 1.1 to 2.5 times as the number average primary particle diameter. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a toner used for electrophotographic image formation, and more particularly to a toner preferable for full-color image formation.

  In recent years, full-color printing using color toners such as yellow toner, magenta toner, and cyan toner has come into practical use in electrophotographic image forming technology. In addition, with the advancement of digital technology, fine dot images can be reproduced by electrophotographic image formation, and with these technologies, images with vivid color tones typified by photographic images and high gradation are used with toner. It has come to be able to produce. In particular, an electrophotographic image forming apparatus can provide a required number of printed materials on demand because the work for generating a plate that has been performed in conventional printing is unnecessary (for example, Patent Document 1). reference). In addition, there is a need to faithfully reproduce the vivid color tone when outputting a display image using computer graphics, etc., focusing on the colorant particle size in the toner and expanding the color gamut and improving color reproducibility. Realized color toners have appeared (for example, see Patent Document 2).

With the development of such technology, the market for prints made using toner has also expanded, and stable light resistance such as displaying posters with vibrant colors outdoors for a long period of time and decorating photos and paintings in the frame. There are also increasing uses under required conditions. For example, it is expected that the posters made using toner will be posted in a strong sunlight environment such as a beach or ski resort for more than a month, and the images can be faded even in such an environment. There is a need to stably maintain the initial color tone. In response to such needs, as a technique for improving the light resistance of a toner image, there is a magenta toner technique that uses a specific pigment and makes the chromaticity of a formed image within a specific range (for example, see Patent Document 3). ).
JP 2007-286148 A JP 2007-298912 A JP-A-11-52565

  However, in Patent Document 3, there is no description that assumes a usage method in which the printed matter is exposed to light for a long period of time, such as posting the produced toner image outdoors or decorating it in a forehead. Patent Document 3 discloses that light resistance evaluation by xenon lamp irradiation was performed and a good result was obtained. However, the irradiation time is 24 hours, and the initial color tone is maintained even in the use environment described above. It was not possible to judge whether the material had enough durability.

  In addition, as a means for maintaining the color tone of the printed image for a long time, measures are taken to increase the amount of the colorant added. Although it was difficult to reproduce, the image quality was liable to deteriorate if the colorant was small.

  As described above, a color image produced by an electrophotographic method has a problem that it is difficult to achieve both improvement in color tone and improvement in light resistance. The present invention stably maintains the initial color tone without causing the image to fade faintly even in an environment where the image is exposed to light for a long period of time, and when a display display image or a photographic image is output, An object is to provide a toner that vividly reproduces an original color tone.

  The present inventor has found that the above-described problems can be solved by the configuration described below, and has completed the present invention.

The invention described in claim 1
“Toner containing at least a resin and a colorant,
The colorant is
The number average primary particle size is from 30 nm to 200 nm, and
A toner having a number average particle diameter of 1.1 to 2.5 times the number average primary particle diameter when contained in the toner particles. ].

  According to the present invention, it is possible to provide a toner capable of exhibiting stable light resistance capable of maintaining an initial color tone without fading even in an environment where the image is exposed to light for a long period of time. did. In other words, by using the toner according to the present invention, the initial color tone can be obtained even when the poster is used for a long time, such as a poster with a vivid color tone, or a picture or painting placed in a forehead. Color toner images that can be stably maintained can be formed. In addition, a vivid color tone can be reproduced at the time of print production. For example, an image can be formed that can faithfully reproduce the color tone of a display display image.

  The present invention relates to a toner containing at least a resin and a colorant, and in particular, the relationship between the number average primary particle size of the colorant contained in the toner and the number average particle size in a state dispersed in the toner particles. Is focused on.

  The present inventor paid attention to the particle size of the colorant in order to achieve both good color tone expression of the toner image and maintenance of stable light resistance, and in particular, the original particle size of the colorant particle and the dispersion in the toner particle. Attention was paid to the relationship with the particle size. In general, a toner image having excellent color characteristics is easily obtained when the particle size of the colorant in the toner is small, and an image excellent in light resistance is easily obtained when the particle size of the colorant in the toner is large. It was known to have a tendency.

  In order to achieve both good color characteristics and light resistance, the present inventor has studied the uniform dispersion conditions of the colorant particles in the toner particles, and the colorant particles are present in the number average primary particle size and the toner particles. It has been found that the above problem is solved when a specific numerical relationship is established between the number average particle size and the number average particle size. That is, the colorant used in the toner has a number average primary particle size of 30 nm or more and 200 nm or less, and 1.1 times the number average primary particle size when contained in the toner particles. It has been found that the above problem is solved when the number average particle diameter is 2.5 times.

  In the present invention, the number average primary particle size of the colorant particles is from 30 nm to 200 nm, and the ratio of the number average primary particle size to the number average particle size of the colorant in the toner particles is from 1.1 to 2. The reason why the problem of the present invention is solved by using a colorant of .5 or less is considered as follows.

  First, the colorant particles having a number average primary particle size of 30 nm to 200 nm are toner particles that do not change the structure of the colorant itself even when the dispersion of the colorant is moderately affected. Can be sufficiently dispersed to a particle size capable of uniform dispersion. That is, when the number average primary particle size of the colorant is reduced, the surface area of the colorant is increased, and the influence of heat and stress applied during dispersion is added to the colorant, which changes the structure of the colorant itself. Therefore, it is considered that a predetermined color tone cannot be obtained.

  In addition, when the number average primary particle size of the colorant is increased, the surface area of the colorant is decreased and the colorant is less susceptible to the effects of heat and stress obtained in the dispersion, and the color tone of the colorant itself is changed. can avoid. However, it is considered that the colorant having a large number average primary particle size is difficult to uniformly disperse in the toner particles and the color tone as the toner is not satisfactory.

  Next, the ratio of the number average primary particle diameter to the number average particle diameter of the colorant in the toner particles (number average particle diameter of the colorant in the toner particles / number average primary particle diameter) is 1.1 to 2. .5, the colorant in the toner particles forms a stable dispersed state to improve the color tone of the toner and also improve the light resistance. That is, when the ratio is smaller than the above range, the initial color tone tends to be improved, but the colorant is easily deteriorated due to the influence of the surface area of the colorant in the toner particles being increased. It is considered that the light resistance of the toner image is lowered. On the other hand, when the ratio is larger than the above range, although the light resistance is improved, it becomes difficult to uniformly disperse in the toner, so that it becomes difficult to express the color tone inherent to the colorant, and a satisfactory color tone is obtained. It is considered that the toner image cannot be formed.

  For the above reasons, the present inventor has a ratio B / A of 1.1 to 2.5, where A is the number average primary particle size and B is the number average particle size when contained in the toner. The present inventors have found that the above problem can be solved by using a colorant having a number average primary particle size of 30 to 200 nm.

  Next, a method for detecting the particle size of the colorant particles will be described. The present invention prepares a colorant particle dispersion using the number average primary particle size of the colorant used in the toner and the colorant, and in the toner particles produced using the colorant particle dispersion. The number average particle size of the colorant is defined.

  The number average primary particle diameter of the colorant, that is, the original particle diameter of the colorant particles before being used for the preparation of the colorant particle dispersion can be calculated by the following procedure. That is, a photograph is taken using a scanning electron microscope (SEM), and the photographed image information is arithmetically processed by an image processing apparatus “Luzex AP (manufactured by Nireco)” to obtain a number average primary particle diameter of the colorant particles. Can be calculated. The equivalent circle equivalent diameter of the photographed colorant particle (the diameter of a circle having the same projected area as the photographed particle) is calculated by the arithmetic processing by “Luzex AP”.

  And a number average primary particle size is calculated based on the measurement result of 100 or more colorant particles. When the colorant particles are photographed in the form of aggregates, the particle size of the primary particles forming the aggregates is defined.

  When calculating the number average primary particle diameter of the colorant particles from a scanning electron microscope (SEM) photograph, first, the colorant particles are set so that the colorant particles can be photographed with a scanning electron microscope (SEM). Specifically, spread the colorant particles on the medicine wrapping paper, paste the conductive double-sided tape on the sample stage, lightly press the opposite side of the surface on the sample stage against the colorant particles on the medicine wrapping paper, Blow away the colorant particles not attached to the sample with a blower, and set the colorant on the sample stage.

  Then, using a sputter coater “Emscope SC500 (manufactured by Emitech)”, a sample is prepared by performing Au—Pa coating (layer thickness: 7 nm) on the colorant particles under a reduced pressure at a coating current of 10 to 15 mA.

In this manner, the colorant particles are fixed on a conductive sample table (grounded) with a conductive double-sided tape, and a photo is taken by irradiating an electron beam from the side of the colorant particles subjected to the sputtering treatment. Here, photographing conditions in the case of using “S-3500N (manufactured by Hitachi, Ltd.)” which is a commercially available scanning electron microscope are as follows. That is,
Vacuum mode: Low vacuum mode Acceleration voltage: 5 kV
Magnification: 250 times Time from the start of electron irradiation to the start of imaging: 3 minutes Sample: Sputtered Sample stage: Aluminum, grounded Others: Photographed using a scale bar Photographed with a scanning electron microscope according to the above procedure The number average primary particle diameter of the colorant particles can be calculated by performing arithmetic processing on the image information of the colorant particles using the above-described image processing apparatus “Luzex AP (manufactured by Nireco)”. In addition to the above-mentioned scanning electron microscope, a scanning electron microscope “JSM-6400F (manufactured by JEOL Ltd.)” can be used under the above conditions.

  Further, the number average particle diameter of the colorant particles dispersed in the toner particles can be calculated by the following procedure, for example. That is, a photograph taken using a transmission electron microscope (TEM) is performed, and the photographed image information is processed by an image processing apparatus “Luzex AP (manufactured by Nireco)” to be dispersed in the toner particles. The number average particle diameter of the agent particles can be calculated. At this time, if the colorant is present as an aggregate in the toner particles, the aggregate is measured as the number average particle diameter.

  The equivalent circle diameter (the diameter of a circle having the same projected area as the photographed particles) of the colorant particles dispersed in the photographed toner particles is calculated by the arithmetic processing by “Luzex AP”. The number average particle diameter of the colorant particles dispersed in the toner particles can be calculated based on the measurement result of 100 or more colorant particles.

  As described above, the number average particle diameter of the colorant particles dispersed in the toner particles can be confirmed by observation with a transmission electron microscope (TEM). Specifically, the measurement section sample prepared by the procedure described later is set in a transmission electron microscope (TEM) set at a magnification of 50,000 times, and observation is performed. It can be confirmed that the colorant particles are dispersed and present.

  Specific examples of the transmission electron microscope (TEM) include “H-9000NAR” (manufactured by Hitachi, Ltd.), “JEM-200FX” (manufactured by JEOL Ltd.), and the like.

  The observation method using a transmission electron microscope is performed by a normal method performed when measuring the cross-sectional structure of the toner particles. For example, it can be performed by the following procedure. First, an observation sample is prepared. The block according to the present invention is prepared by embedding and curing the toner according to the present invention in a room temperature curable epoxy resin. And the sample for a measurement is produced by cutting out the produced block into a 80-200 nm-thick flake shape using the microtome provided with the diamond tooth.

  Next, a photograph of the dispersed particles of the colorant in the toner is taken using a transmission electron microscope (TEM). From the photograph, the cross-sectional structure of the dispersed particles of the colorant in the toner can be visually confirmed. Further, an image processing apparatus such as “Luzex AP (manufactured by Nireco)” is connected to a transmission electron microscope apparatus, and the obtained image information is subjected to arithmetic processing, whereby the colorant particles dispersed in the toner particles are processed. The number average particle size can be calculated. In some cases, the measurement sample may be stained with ruthenium tetroxide, osmium tetroxide, or the like.

  According to the above procedure, the image information of the toner particles photographed with the transmission electron microscope (TEM) is arithmetically processed by the above-described image processing apparatus “Luzex AP (manufactured by Nireco)” to be dispersed in the toner particles. The number average particle size of the colorant particles can be calculated.

  Hereinafter, the present invention will be described in detail.

  The colorant particle dispersion added to the toner according to the present invention can be prepared, for example, by a top-down method in which particles are prepared using a wet dispersion device such as a ball mill, a sand mill, or a bead mill. In the present invention, since a colorant having a number average primary particle size of 30 nm to 200 nm is subjected to a dispersion treatment, it is preferable to use a bead mill type dispersion treatment apparatus using beads for grinding treatment of 15 nm to 200 nm called media.

  In the bead mill type dispersion processing apparatus, the above-described medium is put into a dispersion processing container, and the medium is moved by rotating a rotating shaft provided at the center of the dispersion processing container at high speed. A slurry in which colorant particles to be dispersed are mixed with an aqueous medium is added thereto, the medium is collided with the colorant particles, and the dispersion process is performed by the action of the frictional force generated at this time. After the dispersion treatment, the media is separated from the colorant particles by a centrifugal separator provided in the apparatus. The bead mill type dispersion processing device is also called a media type dispersion processing device. For example, “SC mill, MSC mill (both manufactured by Mitsui Mining Co., Ltd.)” and “Star Mill Nano Getter (manufactured by Ashizawa Finetech Co., Ltd.) And the like.

  In the present invention, when the colorant particle dispersion is prepared, the number average primary particle size when the number average primary particle size contained in the toner is 30 to 200 nm. A colorant particle dispersion is prepared so as to be within a range of 1.1 to 2.5 times the diameter. That is, when preparing a colorant particle dispersion, for example, by controlling factors such as dispersion processing performance, media performance, and the amount of colorant added, the colorant particle dispersion having the above relationship in the toner particles Can be produced.

  Here, the rotational performance and media performance of the dispersion processing apparatus, which are factors to be controlled when preparing the colorant particle dispersion, will be described.

(1) Dispersion processing performance The rotation performance of the dispersion processing apparatus can be controlled by selecting, for example, the shape and peripheral speed of the disk, the supply amount of the dispersion per unit time, and the like. The shape of the disk is a shape that has a plurality of stirring blades called “spindle type” independent, or a plurality of stirring blades joined at the tip to form a circular “flat” or “flat” There is a “pin type” with a pin standing on the disc. Among these, the “pin type” has the ability to easily adjust the colorant particles to a predetermined particle size even under a mild dispersion condition where the disk peripheral speed is slow. On the other hand, it takes time to adjust the colorant particles to a predetermined particle size when the peripheral speed of the “卍” type disk is low.

  The peripheral speed of the disk is preferably 5 m / second to 20 m / second, more preferably 12 m / second to 17 m / second, and particularly preferably 15 m / second. The dispersion supply rate is preferably 2.5 liters / minute to 5.0 liters / minute, and more preferably 3.0 liters / minute to 4.0 liters / minute.

  In addition, if the viscosity of the colorant particle dispersion increases, the dispersion may generate heat due to the action of friction, so the material of the dispersion treatment container is a metal with high thermal conductivity such as stainless steel, carbon steel, zirconia, alumina, etc. It is preferable to make it.

(2) Media performance The performance of media (also referred to as beads) used for dispersion processing can be controlled by selecting, for example, the particle size, material, filling rate, etc. of the media. The media has a particle size of 15 nm to 3.0 mm, preferably 30 nm to 800 nm, and particularly preferably 50 nm to 100 nm in the present invention. From the viewpoint of improving the dispersion processing efficiency, it is preferable to select a medium having a small particle size. The reason is that the smaller the particle size, the greater the amount of media input. The larger the input amount, the greater the contact point (action point) between the media and the colorant particles, so that the dispersion treatment efficiency by the media improves.

  Examples of the material of the media include ceramics, glass, and metal, and specifically include the following. The numbers in parentheses represent specific gravity. That is, soda glass (2.5), sodaless glass (2.5), high specific gravity glass (2.6), quartz (2.2), titania (3.9), silicon nitride (3.2), There are alumina (3.6), zirconia (6.0), stainless steel (8.0), steel (7.8) and the like.

  Since the media contacts the colorant particles in a high-speed rotation state and disperses by the action of the friction generated at that time, the media will not wear out even in such a harsh environment. Durability is required. In addition, in order to efficiently impart a frictional action to the colorant when it comes into contact with the colorant particles, those having a certain specific gravity are preferable. In the present invention, a zirconia medium is preferably used as a medium that satisfies these conditions.

  Further, the filling rate of the medium, which represents the amount of the medium introduced into the dispersion treatment liquid, is preferably 20% to 80%, and in the present invention, 40% to 60% is particularly preferable. The higher the media filling rate, the more likely it is that the chance of contact between the media and colored particles increases. However, when the media filling rate is very high, contact between the media will occur and the contact with colored particles will be reversed. Opportunities decrease. Further, since the contact between the media may cause wear or damage to the media, the media filling rate is preferably within the above range.

(3) Colorant addition amount In the present invention, the colorant addition amount in the aqueous medium is preferably 5% by mass to 40% by mass, more preferably 10% by mass to 25% by mass, and more preferably 10% by mass. ˜15% by weight is particularly preferred. As the amount of the colorant added to the aqueous medium increases, the chance of contact between the individual colorant particles and the media decreases accordingly, so it is necessary to set a longer dispersion treatment time in order to form the colorant particles having a predetermined particle size. There is. Further, when the amount of the colorant added is increased, the viscosity of the colorant particle dispersion increases. That is, since the shear stress and friction that act in the colorant particle dispersion increase, the colorant particle dispersion generates heat due to the action, which causes deterioration of the colorant. From such a viewpoint, in the present invention, the addition amount of the colorant is preferably in the above range.

  In this way, when preparing a colorant particle dispersion using colorant particles having a number average primary particle size of 30 to 200 nm, the number average particle size in the toner particles is selected and controlled by controlling the above conditions. Can be prepared as a colorant particle dispersion having a number average primary particle size of 1.1 to 2.5 times. This will be further described in the examples described later.

  Next, the colorant used in the present invention will be described. In the present invention, the number average primary particle size is 30 nm to 200 nm, and the number average particle size in the toner particles is selected and controlled by a known method when preparing the colorant particle dispersion. The diameter is not particularly limited as long as the colorant is 1.1 to 2.5 times the number average primary particle diameter. Specific examples of the colorant include the following pigments.

First, examples of the yellow colorant include the following pigments. That is,
C. I. Pigment Yellow 3, 9, 35, 36, 65, 74, 83, 98, 111, 139, 153, 181 and the like. Among these, C.I. I. Pigment yellow 74 and C.I. I. Pigment Yellow 139 is preferable.

Examples of the magenta colorant include the following pigments. That is,
C. I. Pigment Red 2, 3, 6, 7, 9, 15, 16, 48: 1, 48: 3, 53: 1, 57: 1, 81: 4, 122, 123, 139, 144, 149, 166, 177, 178, 208, 209, 222, etc. Among these, C.I. I. Pigment red 81: 4 and C.I. I. Pigment Red 48: 3 is preferable.

  Moreover, the following complex compounds 1-4 can also be used as a magenta colorant.

  Further, as the cyan colorant, copper phthalocyanine-based C.I. I. Pigment Blue 15: 3 and Indanthrone C.I. I. In addition to CI Pigment Blue 60 and the like, a silicon phthalocyanine compound represented by the following general formula (I) can be used. In the silicon phthalocyanine compound represented by the general formula (I), a silicon atom (Si) is used as a metal atom (hereinafter also referred to as a central metal atom) located at the center of the phthalocyanine ring.

  Z in the general formula (I) is independently a hydroxy group, chlorine, an aryloxy group having 6 to 18 carbon atoms, an alkoxy group having 1 to 22 carbon atoms, or a compound represented by the following general formula (IV). It is shown.

In general formula (IV), R ¹ , R ² and R ³ are each an alkyl group having 1 to 22 carbon atoms, an aryl group having 6 to 18 carbon atoms, an alkoxy group having 1 to 22 carbon atoms, or the number of carbon atoms It represents 6 to 18 aryloxy groups. R ¹ , R ² and R ³ may be the same group or different groups. R ¹ , R ² and R ³ represent an alkyl group, an aryl group, an alkoxy group or an aryloxy group having the above carbon number, and these groups preferably have 1 to 10 carbon atoms, More preferably, it is 2-8.

Further, A ¹ , A ² , A ³ and A ⁴ in the general formula (I) each independently represent a benzene ring.

The axial ligand Z constituting the compound represented by the general formula (I) is particularly preferably a group represented by the general formula (IV) among the groups described above. R ¹ , R ² and R ³ in the group represented by the general formula (IV) are preferably an alkyl group having 1 to 6 carbon atoms, an aryl group or an alkoxy group, particularly an n-propyl group or an isopropyl group. N-butyl group, isobutyl group and t-butyl group are preferred. R ¹ , R ² and R ³ may be the same group or different groups.

  The phthalocyanine compound represented by the general formula (I) is a phthalocyanine compound having an axial ligand called a tetraazaporphine compound, and specific examples thereof are shown in Table 1. The compound represented by the general formula (I) is It is not limited only to what is shown in Table 1.

  Of the silicon phthalocyanine compounds shown in Table 1, compound (I-4) is particularly preferable.

  Further, the above-described silicon phthalocyanine compound and other colorants can be used in combination, and as a compound that can be used in combination, there is a compound represented by the following general formula (II).

R ₂ constituting the above structural formula represents a hydrogen atom or an organic group. Specific examples of the compound represented by the general formula (II) include the following.

  The content of each colorant in the toner particles is 2 to 12 parts by mass, preferably 4 to 10 parts by mass with respect to 100 parts by mass of the toner particles. In addition, C.I. I. Pigment yellow 74 and C.I. I. When a toner is prepared using a plurality of types of colorants, as in the case of preparing yellow toner using Pigment Yellow 139 in combination, it is preferable that the sum of the colorants be within the above range.

  Next, physical properties such as the particle diameter of the toner according to the present invention will be described.

  The toner according to the present invention preferably has a volume-based median diameter (D50v) of 3 μm or more and 8 μm or less. By setting the volume reference median diameter in the above range, for example, it is possible to faithfully reproduce a very minute dot image at a level of 1200 dpi (dpi; number of dots per inch (2.54 cm)).

  In the present invention, it is an object to make it possible to faithfully reproduce the color of a display display image or a photographic image. However, by setting the volume-based median diameter to a small diameter level in the above range, the color tone is improved and high-definition image quality is achieved. Will also be obtained. For example, when producing a photographic image, a dot image constituting the photographic image can be reproduced as a high-definition image equivalent to or higher than the printed image by using the small-diameter toner. In particular, in a printing field called “on-demand printing” in which a print order is received at a level of several hundred to several thousand copies, high-quality prints containing vivid color tones and high-gradation photographic images can be quickly delivered to the user.

  The volume-based median diameter (D50v diameter) of the toner can be measured and calculated using an apparatus in which a computer system for data processing is connected to “Multisizer 3 (manufactured by Beckman Coulter)”.

  As a measurement procedure, 0.02 g of toner is blended with 20 ml of a surfactant solution (for example, a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of dispersing the toner). After that, ultrasonic dispersion is performed for 1 minute to prepare a toner dispersion. This toner dispersion is poured into a beaker containing “ISOTONII” (manufactured by Beckman Coulter) in the sample stand with a pipette until the measured concentration reaches 5 to 10%, and the measuring machine count is set to 25,000. To measure. The aperture size of the multisizer 3 is 50 μm.

  The toner according to the present invention preferably has a coefficient of variation (CV value) in the volume-based particle size distribution of 2% to 21%, more preferably 5% to 15%.

  The coefficient of variation (CV value) in the volume-based particle size distribution represents the degree of dispersion in the particle size distribution of the toner particles on the volume basis, and is defined by the following equation.

CV value (%) = (standard deviation in number particle size distribution) / (median diameter (D50) in number particle size distribution) × 100
The smaller the CV value, the sharper the particle size distribution, and the larger the toner particle size. That is, since the toner sizes are uniform, it is possible to reproduce the fine dot images and fine lines required for digital image formation with higher accuracy. Further, when printing photographic images, it is possible to create high-quality photographic images at the image level or higher made with printing ink by using small-diameter toners of uniform sizes.

  The toner according to the present invention preferably has a softening point temperature (Tsp) of 70 ° C. or higher and 110 ° C. or lower, more preferably 70 ° C. or higher and 100 ° C. or lower. The colorant used in the toner according to the present invention has a stable property that the spectrum does not change even under the influence of heat. However, by setting the softening point within the above range, The influence of the applied heat can be further reduced. Therefore, since image formation can be performed without imposing a burden on the colorant, it is expected that a wider and more stable color reproducibility is expressed.

  Further, by setting the softening point of the toner within the above range, it becomes possible to fix the toner image at a temperature lower than that of the prior art, and it is possible to form an environmentally friendly toner image that realizes a reduction in power consumption.

The softening point of the toner can be controlled by, for example, the following methods alone or in combination. That is,
(1) The type and composition ratio of monomers used for resin formation are adjusted.
(2) The molecular weight of the resin is adjusted according to the type and amount of chain transfer agent.
(3) Adjust the type and amount of wax.

Further, the method for measuring the softening point temperature of the toner is specifically “Flow Tester CFT-500 (manufactured by Shimadzu Corporation)”, molded into a columnar shape with a height of 10 mm, and at a heating rate of 6 ° C./min. While being heated, a pressure of 1.96 × 10 ⁶ Pa is applied from the plunger, and the pressure is pushed out from a nozzle having a diameter of 1 mm and a length of 1 mm. Thereby, a curve between the plunger drop amount and temperature of the flow tester (softening flow curve) ), And the temperature at the first outflow is the melting start temperature, and the temperature for the drop of 5 mm is the softening point temperature.

  Next, a toner manufacturing method according to the present invention will be described. The toner according to the present invention uses a colorant having a number average primary particle size of 30 nm to 200 nm, and the colorant has a number average primary particle size when the number average particle size of the colorant is contained in the toner particles. The manufacturing method is not particularly limited as long as it is 1.1 times to 2.5 times.

  Hereinafter, toner production by an emulsion association method, which is an example of a toner production method according to the present invention, will be described. Toner preparation by the emulsion association method is performed through the following steps.

(1) Preparation process of resin particle dispersion (2) Preparation process of colorant particle dispersion (3) Aggregation / fusion process of resin particles, etc. (4) Aging process (5) Cooling process (6) Washing process (7 ) Drying step (8) External additive treatment step Hereinafter, each step will be described.

(1) Preparation Step of Resin Particle Dispersion This step is a step of forming resin particles having a size of about 100 nm by introducing a polymerizable monomer that forms resin particles into an aqueous medium and performing polymerization. . It is also possible to form a resin particle containing wax. In this case, resin particles containing the wax can be formed by dissolving or dispersing the wax in the polymerizable monomer and polymerizing it in an aqueous medium.

(2) Preparation Step of Colorant Fine Particle Dispersion This is a step of preparing a colorant particle dispersion by dispersing a colorant in an aqueous medium according to the procedure described above. In particular, in the present invention, a colorant particle dispersion is prepared using a colorant having a number average primary particle size of 30 nm to 200 nm. Then, by producing a toner using the colorant particle dispersion, the number average particle diameter of the colorant in the toner particles is 1.1 to 2.5 times the number average primary particle diameter. is there.

(3) Aggregation / fusion process of resin particles In this process, resin particles and colorant particles are aggregated in an aqueous medium to form particles, and the particles formed by aggregation are fused to form colored particles (external addition treatment). This is a step corresponding to a so-called “step of aggregating resin particles”.

  In this step, these particles are aggregated by adding an aggregating agent such as an alkali metal salt or alkaline earth metal salt represented by magnesium chloride into an aqueous medium in which resin particles and colorant particles are present. Let Next, the aggregated resin particles are fused at the same time as the aggregation progresses by heating the aqueous medium above the glass transition temperature of the resin particles and above the melting peak temperature of the mixture. Then, when agglomeration is advanced and the size of the particles reaches a target, a salt such as salt is added to stop the aggregation.

(4) Ripening step This step is a step of aging the reaction system until the desired average circularity is achieved by heat-treating the reaction system subsequent to the aggregation / fusion step.

(5) Cooling step This step is a step of cooling (rapid cooling) the dispersion of the colored particles. As a cooling treatment condition, cooling is performed at a cooling rate of 1 to 20 ° C./min. The cooling treatment method is not particularly limited, and examples thereof include a method of cooling by introducing a refrigerant from the outside of the reaction vessel, and a method of cooling by directly introducing cold water into the reaction system.

(6) Washing step This step comprises a step of solid-liquid separation of the colored particles from the colored particle dispersion cooled to a predetermined temperature in the above step, and a cake-like aggregate called a wet toner cake that has been solid-liquid separated. It consists of a washing process for removing deposits such as surfactants and flocculants from the colored particles.

  In the washing treatment, water washing is performed until the electric conductivity of the filtrate becomes, for example, about 10 μS / cm. Examples of the solid-liquid separation method include a centrifugal separation method, a vacuum filtration method using Nutsche and the like, a filtration method using a filter press and the like, and are not particularly limited in the present invention.

(7) Drying step This step is a step of drying the washed colored particles to obtain dried colored particles. Examples of the dryer used in this step include a spray dryer, a vacuum freeze dryer, and a vacuum dryer, and a stationary shelf dryer, a mobile shelf dryer, a fluidized bed dryer, and a rotary dryer. It is preferable to use a stirring dryer or the like.

  The water content of the dried colored particles is preferably 5% by mass or less, more preferably 2% by mass or less. In addition, when the dried colored particles are aggregated with weak interparticle attractive force, the aggregate may be crushed. Here, as the crushing processing apparatus, a mechanical crushing apparatus such as a jet mill, a Henschel mixer, a coffee mill, or a food processor can be used.

(8) External additive treatment step This step is a step of adding an external additive or a lubricant to the dried colored particles. The colored particles that have undergone the drying step can be used as toner particles as they are, but the chargeability, fluidity, and cleaning properties of the toner can be improved by adding external additives. As these external additives, known inorganic fine particles, organic fine particles, and aliphatic metal salts can be used, and the addition amount thereof is 0.1 to 10.0% by mass, preferably 0.5% with respect to the whole toner. It is -4.0 mass%. In addition, various external additives can be added in combination. In addition, as a mixing apparatus used when adding an external additive, there exist well-known mechanical mixing apparatuses, such as a turbuler mixer, a Henschel mixer, a Nauta mixer, a V-type mixer, and a coffee mill, for example.

  Through the above steps, the toner according to the present invention can be produced.

  Next, the resin, wax and the like constituting the toner according to the present invention will be described with specific examples.

  First, the resin that can be used in the toner according to the present invention is not particularly limited, but a polymer formed by polymerizing a polymerizable monomer called a vinyl monomer described below is used. This is a typical example. The polymer constituting the resin that can be used in the present invention is a polymer obtained by polymerizing at least one polymerizable monomer, and these vinyl monomers are used alone. Or it is the polymer produced combining multiple types.

Specific examples of vinyl polymerizable monomers are shown below.
(1) Styrene or styrene derivatives Styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert- Butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, etc. (2) Methacrylate derivatives Methyl methacrylate, methacryl Ethyl acetate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethyl methacrylate (3) Acrylic acid ester derivatives Methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, phenyl acrylate, etc. (4) olefins Ethylene, propylene, isobutylene, etc. (5) Vinyl esters Vinyl propionate, vinyl acetate, vinyl benzoate, etc. (6) Vinyl ether (7) Vinyl ketones Vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, etc. (8) N-vinyl compounds N-vinyl carbazole, N-vinyl indole (9) Others Vinyl compounds such as vinyl naphthalene and vinyl pyridine, acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, acrylamide, etc. Also, the resin that can be used for the toner according to the present invention As the vinyl polymerizable monomer, those having an ionic dissociation group shown below can be used. In particular, the colorant of the present invention has weak alkalinity as described above, and the one having an ionic dissociation group such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group in the side chain of the monomer is used. Further, the dispersibility in the resin can be further improved, which is preferable. Specifically, there are the following.

  First, those having a carboxyl group include acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumaric acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, and the like. Examples of those having a sulfonic acid group include styrenesulfonic acid, allylsulfosuccinic acid, 2-acrylamido-2-methylpropanesulfonic acid, and examples of those having a phosphoric acid group include acid phosphooxyethyl methacrylate.

  Moreover, it is also possible to produce a resin having a crosslinked structure by using the following polyfunctional vinyls. Specific examples of polyfunctional vinyls are shown below.

Divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, etc. Next, the present invention Examples of the wax that can be used for the toner according to the present invention include the following known waxes.
(1) Polyolefin wax Polyethylene wax, polypropylene wax, etc. (2) Long chain hydrocarbon wax, paraffin wax, sazol wax, etc. (3) Dialkyl ketone wax, distearyl ketone, etc. (4) Ester wax Carnauba wax, Montan Wax, trimethylolpropane tribehenate, pentaerythritol tetramyristate, pentaerythritol tetrastearate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerol tribehenate, 1,18-octadecanediol di Stearate, trimellitic trimellitic acid, distearyl maleate, etc. (5) Amide wax Ethylenediamine dibehenyl amide, trimellitic acid triste The melting point of Riruamido such as wax is usually from 40 to 125 ° C., preferably from 50 to 120 ° C., more preferably from 60 to 90 ° C.. By setting the melting point within the above range, the heat-resistant storage stability of the toner is ensured, and stable toner image formation can be performed without causing cold offset or the like even when fixing at a low temperature. Further, the wax content in the toner is preferably 1% by mass to 30% by mass, and more preferably 5% by mass to 20% by mass.

  Next, the toner according to the present invention includes inorganic fine particles having an average primary particle size of 4 to 800 nm, organic fine particles having an average primary particle size of 10 to 2000 nm, and the like as external additives (= external additives) in the production process. These particles can be added to make a toner.

  By adding the external additive, the fluidity and chargeability of the toner are improved, and the cleaning property is improved. The type of external additive is not particularly limited, and examples thereof include inorganic fine particles, organic fine particles, and lubricants described below.

  As the inorganic fine particles, for example, inorganic oxide particles such as silica, titania, and alumina are preferably used, and these inorganic fine particles are preferably hydrophobized with a silane coupling agent or a titanium coupling agent. .

  As the organic fine particles, spherical particles having an average primary particle diameter of about 10 to 2000 nm can be used. Examples of the organic fine particles include polystyrene, polymethyl methacrylate, and styrene-methyl methacrylate copolymer. Specific examples of inorganic fine particles and organic fine particles will be described later.

  As the inorganic fine particles, conventionally known fine particles can be used. For example, silica, titania, alumina, strontium titanate fine particles and the like are preferable. Moreover, what hydrophobized these inorganic fine particles as needed can also be used.

  Specific examples of the silica fine particles include commercially available products R-805, R-976, R-974, R-972, R-812, R-809 manufactured by Nippon Aerosil Co., Ltd., HVK-2150 manufactured by Hoechst, H -200, commercially available products TS-720, TS-530, TS-610, H-5, MS-5, etc. manufactured by Cabot Corporation.

  As the titania fine particles, for example, commercially available products T-805 and T-604 manufactured by Nippon Aerosil Co., Ltd., commercially available products MT-100S, MT-100B, MT-500BS, MT-600, MT-600SS, JA- 1. Commercial products TA-300SI, TA-500, TAF-130, TAF-510, TAF-510T manufactured by Fuji Titanium Co., Ltd. Commercial products IT-S, IT-OA, IT-OB, IT- manufactured by Idemitsu Kosan Co., Ltd. OC etc.

  Examples of the alumina fine particles include commercial products RFY-C and C-604 manufactured by Nippon Aerosil Co., Ltd., and commercial products TTO-55 manufactured by Ishihara Sangyo Co., Ltd.

  As the organic fine particles, spherical organic fine particles having an average primary particle diameter of about 10 to 2000 nm can be used. Specifically, polymer particles such as polystyrene, polymethyl methacrylate, and styrene-methyl methacrylate copolymer can be used.

  In order to further improve the cleaning property and transfer property, a lubricant represented by the following higher fatty acid metal salt can be used. For example, zinc stearate, aluminum, copper, magnesium, calcium, etc., zinc oleate, manganese, iron, copper, magnesium, etc., zinc palmitate, copper, magnesium, calcium, etc., linoleic acid There are salts of zinc, calcium and the like, and zinc and calcium of ricinoleic acid.

  The recording material used when forming an image using the toner according to the present invention is not particularly limited as long as it can hold a toner image. When using, an image having excellent color tone and light resistance can be formed. Specifically, in addition to plain paper and high-quality paper from thin paper to thick paper, there are coated printing papers such as art paper and coated paper that are often used in the printing field. In addition, it is possible to form images on various supports such as commercially available Japanese paper, postcard paper, OHP plastic film, and cloth.

  The toner according to the present invention can be used as a non-magnetic one-component developer in addition to a two-component developer mixed with a carrier. When the toner according to the present invention is used as a two-component developer, as a carrier, magnetic particles made of a known material such as a metal such as iron, ferrite, and magnetite, and an alloy of the metal and a metal such as aluminum and lead are used. Although used, ferrite particles are particularly preferable. Examples of the carrier include a coat carrier obtained by coating the surface of magnetic particles with a coating agent such as a resin, and a binder type carrier obtained by dispersing magnetic fine powder in a binder resin.

  The coating resin that constitutes the coat carrier is not particularly limited, and examples thereof include polyolefin resins, polystyrene resins, styrene-acrylic copolymer resins, silicone resins, polyester resins, and fluororesins. Moreover, well-known thing can be used for binder resin which comprises a binder-type carrier, For example, there exist a styrene-acrylic-type copolymer resin, a polyester resin, a fluororesin, a phenol resin etc.

  The carrier preferably has a volume-based median diameter of 20 to 100 μm, more preferably 20 to 60 μm, since a high-quality image can be obtained and carrier fogging is suppressed. The volume-based median diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.

  Next, an example of an image forming apparatus that forms an image using the toner according to the present invention will be described. FIG. 1 is a schematic diagram illustrating an example of an image forming apparatus capable of forming a full color image with a two-component developer.

  In FIG. 1, 1Y, 1M, 1C, 1K are photosensitive members, 4Y, 4M, 4C, 4K are developing devices (developing means), 5Y, 5M, 5C, 5K are primary transfer rolls as primary transfer means, 5A is a secondary transfer roll as a secondary transfer means, 6Y, 6M, 6C and 6K are cleaning devices, 7 is an intermediate transfer body unit, 24 is a heat roll type fixing device, and 70 is an intermediate transfer body.

  This image forming apparatus is called a tandem color image forming apparatus, and includes a plurality of sets of image forming units 10Y, 10M, 10C, and 10K, an endless belt-shaped intermediate transfer body unit 7 as a transfer unit, and a recording member P. It has an endless belt-like paper feeding and conveying means 21 for conveying and a heat roll type fixing device 24 as a fixing means. A document image reading device SC is disposed on the upper part of the main body A of the image forming apparatus.

  An image forming unit 10Y that forms a yellow image as one of the different color toner images formed on each photoconductor is arranged around a drum-shaped photoconductor 1Y as the first photoconductor and the photoconductor 1Y. The charging unit 2Y, the exposure unit 3Y, the developing unit 4Y, the primary transfer roll 5Y as the primary transfer unit, and the cleaning unit 6Y are provided. The image forming unit 10M that forms a magenta image as another different color toner image includes a drum-shaped photoconductor 1M as a first photoconductor, and a charge disposed around the photoconductor 1M. Means 2M, exposure means 3M, developing means 4M, primary transfer roll 5M as primary transfer means, and cleaning means 6M. In addition, an image forming unit 10C that forms a cyan image as one of toner images of different colors is a drum-shaped photoconductor 1C as a first photoconductor, and a charge disposed around the photoconductor 1C. Means 2C, exposure means 3C, developing means 4C, primary transfer roll 5C as primary transfer means, and cleaning means 6C.

  Furthermore, an image forming unit 10K that forms a black image as one of other different color toner images is disposed around the photosensitive member 1K as a drum-shaped photosensitive member 1K as a first photosensitive member. It has a charging means 2K, an exposure means 3K, a developing means 4K, a primary transfer roll 5K as a primary transfer means, and a cleaning means 6K.

  The endless belt-like intermediate transfer body unit 7 has an endless belt-like intermediate transfer body 70 as an intermediate transfer endless belt-like second image carrier that is wound around a plurality of rolls and is rotatably supported.

  Each color image formed by the image forming units 10Y, 10M, 10C, and 10K is sequentially transferred and synthesized on the rotating endless belt-shaped intermediate transfer body 70 by the primary transfer rolls 5Y, 5M, 5C, and 5K. A color image is formed. A recording member P such as a sheet as a transfer material accommodated in the sheet feeding cassette 20 is fed by the sheet feeding / conveying means 21, passes through a plurality of intermediate rolls 22 A, 22 B, 22 C, 22 D, and a registration roll 23, and is secondary. A color image is transferred onto the recording member P at a time by being conveyed to a secondary transfer roll 5A as a transfer means. The recording member P to which the color image has been transferred is fixed by the heat roll type fixing device 24, is sandwiched by the paper discharge roll 25, and is placed on the paper discharge tray 26 outside the apparatus.

  On the other hand, after the color image is transferred to the recording member P by the secondary transfer roll 5A, the residual toner is removed by the cleaning unit 6A from the endless belt-shaped intermediate transfer body 70 in which the recording member P is separated by curvature.

  During the image forming process, the primary transfer roll 5K is always in pressure contact with the photoreceptor 1K. The other primary transfer rolls 5Y, 5M, and 5C are in pressure contact with the corresponding photoreceptors 1Y, 1M, 1C, and 1R, respectively, only during color image formation.

  The secondary transfer roll 5A comes into pressure contact with the endless belt-shaped intermediate transfer body 70 only when the recording member P passes through the secondary transfer roll 5A and secondary transfer is performed.

  In this manner, toner images are formed on the photoreceptors 1Y, 1M, 1C, 1R, and 1K by charging, exposure, and development, and the toner images of the respective colors are superimposed on the endless belt-shaped intermediate transfer body 70 and recorded collectively. The image is transferred to the member P and fixed by the fixing device 24 by pressure and heating. The photoreceptors 1Y, 1M, 1C, and 1K after transferring the toner image to the recording member P are subjected to the above-described charging, exposure, and development cycle after the toner remaining on the photoreceptor is removed by the cleaning device 6A. The next image formation is performed.

  A full-color image forming method using a non-magnetic one-component developer includes, for example, an image forming apparatus in which the developing means 4 for the two-component developer described above is replaced with a known developing means for a non-magnetic one-component developer. It can be realized by using it.

  In addition, the fixing method that can be performed by the image forming method according to the present invention is not particularly limited, and can be handled by a known fixing method. Known fixing methods include a roller fixing method comprising a heating roller and a pressure roller, a fixing method comprising a heating roller and a pressure belt, a fixing method comprising a heating belt and a pressure roller, and a heating belt and a pressure belt. Belt fixing method and the like, and any method may be used. As a heating method, a heating method such as a halogen lamp method or an IH fixing method can be employed.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to the content as described below.

1. 1. Preparation of colorant particle dispersion 1-1. Preparation of “Yellow Particle Dispersion Y1 to Y5” (1) Preparation of “Yellow Particle Dispersion Y1” In a stainless steel dispersion treatment vessel, 253 parts by mass of sodium n-dodecyl sulfate was charged into 2372 parts by mass of ion-exchanged water. A surfactant solution (aqueous medium) was prepared by dissolving and stirring. In this surfactant aqueous solution,
C. I. Pigment Yellow 74 337.5 parts by mass C.I. I. 37.5 parts by mass of Pigment Yellow 139 was added, and dispersion treatment was performed at room temperature for 2.5 hours using “Star Mill Nano Getter DMR-110 (manufactured by Ashizawa Finetech Co., Ltd.)”. The above C.I. I. The number average primary particle size of Pigment Yellow 74 and 139 was 150 nm.

The distributed processing conditions by the distributed processing apparatus are as follows. That is,
Disc condition Shape Pin type Peripheral speed 15m / sec Colorant particle dispersion supply rate 3.5L / min Media condition Material Zirconia Particle size 50nm
50% filling rate
Dispersion treatment time 2 hours Material of dispersion treatment container Stainless steel “Yellow particle dispersion Y1” was prepared by the dispersion treatment. The volume-based median diameter of the colorant particles in “Yellow Particle Dispersion Y1” was measured using the dynamic scattering particle size analyzer “MICROTRAC UPA-150” (manufactured by HONEYWELL) under the following measurement conditions. It was.

Sample refractive index 1.59
Sample specific gravity 1.05 (in terms of spherical particles)
Solvent refractive index 1.33
Solvent viscosity 0.797 (30 ° C), 1.002 (20 ° C)
0-point adjustment Ion-exchanged water was added to the measurement cell for preparation.

(2) Preparation of “Yellow Particle Dispersion Y2 to Y5” In the preparation of “Yellow Particle Dispersion Y1,” the same treatment except that the media particle size and dispersion treatment time were changed to the conditions shown in Table 2 described later. To prepare “yellow particle dispersions Y2 to Y5”.

1-2. Production of “Magenta Particle Dispersion M1 to M5” In place of the yellow colorant used in the production of “Yellow Particle Dispersion Y1”,
C. I. Pigment Red 81: 4 175 parts by mass C.I. I. Pigment Red 48: 3 175 parts by mass and the same treatment was performed except that the media particle size and dispersion treatment time were changed to the conditions shown in Table 2 to be described later, and "Magenta Particle Dispersions M1 to M5" Produced. The above C.I. I. The number average primary particle size of Pigment Red 81: 4 and 48: 3 was 120 nm.

1-3. Preparation of “Cyan Particle Dispersion C1 to C9” (1) Preparation of “Cyan Particle Dispersion C1 to C5” In place of the yellow colorant used in the preparation of “Yellow Particle Dispersion Y1”, Table 1 While changing to add 340 parts by mass of “Compound I-4”, the particle size of the media and the dispersion treatment time were changed to the conditions shown in Table 2 described later. Otherwise, the same treatment was performed to prepare “Cyan particle dispersions C1 to C5”. The “compound I-4” had a number average primary particle size of 90 nm.

(2) Preparation of “Cyan Particle Dispersion C6-C9” Solvent Species and Solvents Used for Crystal Precipitation in Preparation of “Compound I-4” Used in Preparation of “Cyan Particle Dispersion C1-C5” By adjusting the mixing ratio by a known method, “compound I-4” having a number average primary particle size of 30 nm, 200 nm, 250 nm, and 25 nm was produced.

  In the preparation of the “cyan particle dispersions C1 to C5”, the above-mentioned “compound I-4” having the number average primary particle diameter is used, and the particle diameter of the media and the dispersion treatment time are set as shown in Table 2 described later Except for the change, the same treatment was performed to prepare “Cyan Particle Dispersions C6 to C9”.

  Table 2 shows the performance of “yellow particle dispersions Y1 to Y5”, “magenta particle dispersions M1 to M5”, and “cyan particle dispersions C1 to C9” prepared by the above procedure. The number average particle size B in the toner particles in the table is based on a photographic image taken using a commercially available transmission electron microscope (TEM) after the preparation of each toner by the procedure described below. .

2. Preparation of toner particles (1) Preparation of “resin particles 1” (a) First stage polymerization An anionic surfactant having the following structural formula in a reaction vessel equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen introducing device ( 4 parts by mass of sodium dodecyl sulfate) was dissolved in 3040 parts by mass of ion-exchanged water to prepare a surfactant aqueous solution.

Anionic surfactant: C ₁₀ H ₂₁ (OCH ₂ CH ₂ ) ₂ SO ₃ Na
In the surfactant aqueous solution, a polymerization initiator solution in which 10 parts by mass of potassium persulfate (KPS) was dissolved in 400 parts by mass of ion-exchanged water was added, and the liquid temperature was raised to 75 ° C. A polymerizable monomer solution was added dropwise over 1 hour.

Styrene 532 parts by weight n-butyl acrylate 200 parts by weight Methacrylic acid 68 parts by weight n-octyl mercaptan 16.4 parts by weight After the dropwise addition of the polymerizable monomer solution, the polymerization reaction is carried out by heating and stirring at 75 ° C. for 2 hours. (First stage polymerization) was performed to prepare “resin particle dispersion (1H)” containing “resin particles (1h)”. The formed “resin particles (1h)” had a weight average molecular weight of 16,500.

(B) Second-stage polymerization Styrene 101.1 parts by mass n-butyl acrylate 62.2 parts by mass Methacrylic acid 12.3 parts by mass n-octyl mercaptan 1.75 parts by mass The above compound was charged into a flask equipped with a stirrer. Thus, a polymerizable monomer solution was prepared. Then add the following wax,
Paraffin wax “HNP-57 (manufactured by Nippon Wax Co., Ltd.)” 93.8 parts by mass A monomer solution containing paraffin wax was prepared by heating the internal temperature to 90 ° C. and dissolving the wax.

  On the other hand, 3 parts by weight of the anionic surfactant used in the first stage polymerization was dissolved in 1560 parts by weight of ion exchange water to prepare a surfactant aqueous solution, which was heated to an internal temperature of 98 ° C. To this surfactant aqueous solution, 32.8 parts by mass (in terms of solid content) of the “resin particles (1h)” was added, and further a monomer solution containing the paraffin wax was added. After that, by performing a mixing dispersion treatment for 8 hours using a mechanical disperser “CLEARMIX (manufactured by M Technique Co., Ltd.)” having a circulation path, an oil droplet particle dispersion containing oil droplet particles having a dispersed particle diameter of 340 nm Was prepared.

  Next, a polymerization initiator solution in which 6 parts by mass of potassium persulfate is dissolved in 200 parts by mass of ion-exchanged water is added to the oil droplet particle dispersion, and the mixture is heated and stirred at 98 ° C. for 12 hours. Two-stage polymerization) was performed. A “resin particle dispersion (1HM)” containing “resin particles (1hm)” was produced by the polymerization reaction. The formed “resin particles (1 hm)” had a weight average molecular weight of 23,000.

(C) Third-stage polymerization A polymerization initiator solution obtained by dissolving 5.45 parts by mass of potassium persulfate in 220 parts by mass of ion-exchanged water in the “resin particle dispersion (1HM)” formed by the second-stage polymerization. Was added dropwise over a period of 1 hour under a temperature condition of 80 ° C.

Styrene 293.8 parts by mass n-butyl acrylate 154.1 parts by mass n-octyl mercaptan 7.08 parts by mass After dropwise addition of the polymerizable monomer solution, the polymerization reaction is performed by heating and stirring for 2 hours (third stage polymerization). After that, it was cooled to 28 ° C. to prepare “resin particle dispersion 1” containing “resin particles 1”. The formed “resin particle 1” had a weight average molecular weight of 26,800.

(2) Preparation of “toner particle 1Y” (a) Aggregation / fusion process In a reaction vessel equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen introducing device,
420.7 parts by mass of resin particles 1 (solid content conversion)
Ion-exchanged water 500 parts by mass Yellow particle dispersion Y1 5.3 parts by mass (solid content conversion)
4.5 parts by mass of metal compound particle dispersion 1 (in terms of solid content)
Was added to adjust the internal temperature to 30 ° C. while stirring, and then the pH was adjusted to 10 by adding a 5 mol / liter aqueous sodium hydroxide solution.

  Next, an aqueous solution in which 2 parts by mass of magnesium chloride hexahydrate was dissolved in 1000 parts by mass of ion-exchanged water was added over 10 minutes at 30 ° C. with stirring. After the addition, the mixture was allowed to stand for 3 minutes and then the temperature increase was started. The system was heated to 75 ° C. over 60 minutes to aggregate the particles. Subsequently, when the average particle diameter of the aggregated particles was measured with “Coulter Multisizer 3 (manufactured by Beckman Coulter)” and the volume-based median diameter reached 6.5 μm, 8.2 parts by mass of sodium chloride was exchanged with ion-exchanged water. An aqueous solution dissolved in 50 parts by mass was added to stop particle growth.

  Further, the temperature of the liquid was set to 80 ° C., and the mixture was heated and stirred for 4 hours to continue the fusion, thereby producing “Toner Particle Dispersion 1Y”. With respect to “Toner Particle Dispersion 1Y”, the average circularity of the toner particles was measured using “FPIA2100 (manufactured by Sysmex Corporation)” and found to be 0.940.

(C) Washing / Drying Step Next, the produced “toner particle dispersion 1Y” was filtered, and the washing treatment was repeated using ion-exchanged water at 45 ° C. After completion of the cleaning treatment, drying treatment was performed with hot air at 40 ° C. to produce “toner particles 1Y” having a volume-based median diameter of 6.2 μm.

(3) External Addition Treatment To the produced “Toner Particles 1Y”, the following external additive hexamethylsilazane-treated silica (average primary particle size 12 nm) 0.6 parts by mass n-octylsilane-treated titanium dioxide (average primary) Particle size 24nm)
0.8 parts by weight were added. The external addition treatment was performed by using a “Henschel mixer (manufactured by Mitsui Miike Mining Co., Ltd.)” and mixing under the conditions of a peripheral speed of a stirring blade of 35 m / second, a treatment temperature of 35 ° C., and a treatment time of 15 minutes. In this way, “Toner 1Y” was produced. The produced “Toner 1Y” had no change in shape and particle size before and after the external addition process.

(4) Preparation of “Toners 2Y to 5Y” In the preparation of “Toner 1Y”, instead of “Yellow Particle Dispersion Y1” used in the aggregation / fusion process, “Yellow Particle Dispersion Y2” shown in Table 2 above is used. “Toners 2Y to 5Y” which are yellow toners were prepared in the same procedure except that “˜Y5” was used. “Toners 2Y to 5Y” each had a volume-based median diameter of 6.2 μm, which is the same as “Toner 1Y”.

(5) Preparation of “Toners 1M to 5M” In the preparation of “Toner 1Y”, instead of 5.3 parts by weight (in terms of solid content) of “yellow particle dispersion Y1” used in the aggregation / fusion process, It changed into 6.3 mass parts (solid content conversion) of "Magenta particle dispersion M1-M5" shown in Table 2. Other than this, “toners 1M to 5M” which are magenta toners were prepared in the same procedure. The volume-based median diameter of “Toners 1M to 9M” was 6.2 μm, the same as “Toner 1Y”.

(6) Preparation of “Toners 1C to 9C” In the preparation of “Toner 1Y”, instead of 5.3 parts by weight (in terms of solid content) of “Yellow particle dispersion Y1” used in the aggregation / fusion process, It changed to 5.2 mass parts (solid content conversion) of "Cyan particle dispersion C1-C9" shown in Table 2. Other than this, “toners 1C to 9C”, which are cyan toners, were prepared in the same procedure. The volume-based median diameter of “Toners 1C to 9C” was 6.2 μm, the same as “Toner 1Y”.

(7) "Black toner K"
In the “yellow particle dispersion Y1” used in the preparation of the “toner 1Y”, the “carbon black particle dispersion liquid” was prepared in the same procedure except that 345 parts by mass of “carbon black; Mogal L” was used instead of the yellow colorant. K1 "was produced. Next, in the preparation of the “toner 1Y”, the same procedure was used except that 5.2 parts by weight (in terms of solid content) of the “carbon black particle dispersion K1” was used instead of the “yellow particle dispersion Y1”. “Toner K” was prepared.

3. Evaluation experiment 3-1. Preparation of Developer Ferrite having a volume average particle diameter of 50 μm coated with methyl methacrylate and cyclohexyl methacrylate resin on each of the “toners 1Y to 5Y”, “toners 1M to 5M”, “toners 1C to 9C”, and “toner K” A developer having a toner concentration of 6% was prepared by mixing the carrier. That is, yellow “developers 1Y to 5Y”, magenta “developers 1M to 5M”, cyan “developers 1C to 9C”, and “black developer K” were prepared.

3-2. Evaluation Evaluation is performed by combining a developer as shown in Table 3 with a commercially available composite printer “bizhub Pro C500 (manufactured by Konica Minolta Business Technologies, Inc.)” corresponding to the two-component development type image forming apparatus of FIG. Mounted.

<Evaluation of color tone and light resistance by color gamut area measurement>
A test chart for color gamut evaluation is output by the following procedure, and the color gamut measurement of the output test chart is performed to obtain a color gamut evaluation result in the initial stage. Thereafter, 10,000 lux was irradiated for 14 days with a xenon fade meter, and the light resistance was evaluated by measuring the color gamut of the test chart after 14 days in the same procedure as in the initial stage. As a xenon fade meter, “XENONTESTER XW-150 (manufactured by Shimadzu Corporation)” was used.

  The test chart for color gamut measurement is output in the default mode using the “bizhub PRO C6500 (manufactured by Konica Minolta Business Technologies, Inc.)”, and the test chart for color gamut measurement is “Spectrolina / Scan Bundle (Gretag Macbeth) "under the following conditions.

Measurement conditions Light source: D50 light source Observation field: 2 °
Concentration: ANSI T
White standard: Abs
Filter: UV Cut
Measurement mode: Reflectance Language: Japan
The color gamut measurement is evaluated by solid images of yellow (Y), magenta (M), cyan (C), red (R), blue (B), and green (G) (2 cm × 2 cm). Is made. A color gamut composed of Y / M / C / R / G / B by these solid images is represented by a ^* -b ^* coordinates, and the area is measured as the color gamut area. The color reproduction range is evaluated with the initial color gamut area produced in Comparative Example 2 as 100. An initial color gamut area value of 110 or more is considered acceptable for the color tone. Regarding light resistance, a color gamut area value of 110 or more and a color gamut area reduction rate of 5.0% or less are accepted.

  In the above evaluation, as described above, “black developer K” is also installed in the apparatus, but the produced yellow (Y), magenta (M), cyan (C), red (R), blue (B), Each solid image of green (G) is produced with yellow, magenta, and cyan color developers.

  The results are shown in Table 3.

  As is apparent from the results in Table 3, “Examples 1 to 5” using the color toner having the configuration of the present invention have a good color gamut area in the initial stage and also have good results in light resistance. Obtained. On the other hand, “Comparative Examples 1 to 4” using color toners that do not satisfy the constituent requirements of the present invention did not provide a good color gamut area at the initial stage. Further, it was confirmed that light resistance could not be obtained even if a good color gamut area was obtained in the initial stage.

1 is a schematic diagram illustrating an example of a tandem full-color image forming apparatus capable of two-component development type image formation.

Explanation of symbols

1 (1Y, 1M, 1C, 1K) Photoconductor 2 (2Y, 2M, 2C, 2K) Charging unit 3 (3Y, 3M, 3C, 3K) Exposure unit 4 (4Y, 4M, 4C, 4K) Developing unit 5 ( 5Y, 5M, 5C, 5K, 5A) Transfer roll 6 (6Y, 6M, 6C, 6K) Cleaning device 7 Intermediate transfer unit 10 (10Y, 10M, 10C, 10K) Image forming unit 24 Heat roll fixing device 70 Intermediate Transcript

Claims (1)

A toner containing at least a resin and a colorant,
The colorant is
The number average primary particle size is from 30 nm to 200 nm, and
A toner having a number average particle diameter of 1.1 to 2.5 times the number average primary particle diameter when contained in the toner particles.

Images